Soft tissues, such as ligaments, tendons, and muscles, are attached to a large portion of the human skeleton. In particular, many ligaments and tendons are attached to the bones which form joints, such as shoulder and knee joints. A variety of injuries and conditions require attachment or reattachment of soft tissue to bone. For example, when otherwise healthy tissue has been torn away from a bone, surgery is often required to reattach the tissue to the bone to allow healing and natural reattachment to occur.
A number of devices and methods have been developed to attach soft tissue to bone. These include screws, staples, cement, suture anchors, and sutures alone. Some of the more successful methods involve use of a suture anchor to attach a suture to the bone, and tying the suture in a manner that holds the tissue in close proximity to the bone.
Proper attachment of soft tissue to bone requires that it be placed in the anatomically correct position to promote optimal healing. Conventional methods for attaching soft tissue to bone have typically used anchors through which a suture can be pulled to draw a piece of soft tissue attached to the suture into proximity of a surface of the bone after the anchor is inserted in a predrilled bone cavity. Such methods then require a free end or ends of the suture to be tied off to hold the soft tissue in place. More recently, however, “knotless” suture anchors have been utilized to eliminate the need to tie off the free end(s) of the suture. Many such “knotless” suture anchor systems control tension on tissue by a depth to which the anchor is driven into bone. Other “knotless” suture anchor systems utilize a sleeve that receives the anchor for locking the suture. Suture anchor systems with sliding knots for repairing torn or damaged tissue have also been traditionally utilized.
The soft tissue may be attached to the bone during open surgery, or during closed (e.g., arthroscopic) surgical procedures. Closed surgical procedures can be preferred since they are less invasive and are less likely to cause patient trauma. In a closed surgical procedure, a surgeon performs diagnostic and therapeutic procedures at a surgical site through small incisions, called portals, using instruments specially designed for this purpose. One problem encountered in the less invasive, closed surgical procedures is that the surgeon has significantly less room to perform the required manipulations at the surgical site than in open surgery. Thus, devices and methods are needed which will allow a surgeon to effectively and easily attach soft tissue to bone in the small spaces provided by less invasive surgical procedures.
Accordingly, there remains a need for improved devices, systems, and methods for securing soft tissue to bone.